JPH07176795A - Formation of chip led lens using potting resin - Google Patents

Abstract

PURPOSE:To provide a method for the formation of a lens wherein resin will not flow even if slightly too much of it is potted. CONSTITUTION:The end 3 of the resin filling section 2 of a case 1 with a LED luminous element formed is coated with a substance of low surface free energy to form a coating film 5. Resin is injected into the resin filling section 2, and heated and hardened. Thus resin is repelled by the coating film 5 on the end 3 of the case 1, and its flow is thereby prevented.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of forming a lens of a chip LED with a potting resin.

[0002]

2. Description of the Related Art Chip LEDs by potting resin
In the case of forming the lens, the resin is injected into the resin-filled portion of the case (package) provided with the LED light emitting element, and the resin is heated and cured to form the lens. that time,
Depending on the shape of the lens, the surface of the resin is convex or flat.

[0003]

When potting the surface of the resin flat, as shown in FIG. 4, the resin filling portion 12 of the case 10 provided with the LED light emitting element (not shown) is used.
For example, when the epoxy resin 17 is flatly injected into the end face 13 on the resin filling portion 12 side of the case 10 [see (a) of FIG. 4], and then the epoxy resin 17 is heated and cured, the epoxy resin 17 becomes The volume decreases due to curing / shrinking, and after curing, the case 10 is recessed from the end surface 13 (see FIG. 4B).

On the other hand, when the curing / shrinkage amount of the epoxy resin shown in FIG. 4 (b) is estimated in advance, or when a convex lens is formed, the epoxy resin as shown in FIG. 5 (a) is used. A large amount of 17 is injected into the resin filling portion 12 of the case 10, and the surface of the epoxy resin 17 is the end surface 13 of the case 10.
Make it a convex shape. However, if the resin is heated and cured in that state, the epoxy resin 17 flows onto the end surface 13 of the case 10 due to its viscosity decrease during curing, and the surface becomes flat [see (b) of FIG. 5], and the curing is completed. Then, the volume of the epoxy resin 17 decreases due to the contraction as described above, and the epoxy resin 17 becomes a concave state (see (c) of FIG. 5).

As described above, in the conventional forming method, there is a problem that it is difficult to cure the surface of the resin to be flat or convex because the resin flows and the curing shrinkage occurs. Therefore, an object of the present invention is to provide a lens forming method in which the resin does not flow even if a large amount of resin is potted.

[0006]

In order to achieve the above-mentioned object, a method of forming a lens of a chip LED using a potting resin of the present invention is such that a resin is potted in a resin-filled portion of a case provided with an LED light-emitting element to form a chip LED. In the lens forming method for forming a lens, the end face of the case on the resin-filled portion side is coated with a substance having a small surface free energy, and then the resin is injected into the resin-filled portion of the case to heat and cure the resin. Is characterized by.

[0007]

In this forming method, before potting the resin,
In order to coat the end surface of the case on the resin-filled side with a substance with a small surface free energy, the resin is potted into a convex shape from the end surface of the case, and then the resin is heated and cured to reduce its viscosity. Becomes more fluid, and even if the resin tries to flow onto the end surface of the case,
The resin is repelled by the coating film on the end face of the case,
Maintains the convex shape and cures in the convex state. Therefore, even if a large amount of resin is injected into the resin-filled portion of the case, the resin does not flow due to heating and curing, and the convex lens of the chip LED can be easily formed.

However, the substance having a small surface free energy used in the present invention may be any substance capable of repelling the resin to be potted, such as a fluorine-based substance (eg, polyfluoroethylene, polyvinyl fluoride, carbon fluoride, etc.). (Including fluorine atoms in the molecule), silicon-based substances (for example, linear polymer silicon such as polyorganosiloxane)
Etc. are illustrated.

As a method for coating the above-mentioned substances, existing coating techniques such as printing, painting, sputtering, etc. may be used. The resin to be injected into the resin-filled portion of the case may be the same as the conventional one, and epoxy resin, urethane resin, polycarbonate resin, acrylic resin, silicone resin, etc. are shown.

[0010]

EXAMPLES The lens forming method of the present invention will be described below based on examples. In FIG. 1, an LED light emitting element (not shown) is provided at the bottom of a resin-filled portion 2 of a case (package) 1 made of resin or ceramic. First, the end face 3 on the resin-filled portion 2 side of the case 1 (hatched area in the figure) is coated with an appropriate substance from the above as a substance having a small surface free energy by coating or sputtering to coat the end face 3. Coat with membrane 5. Next, for example, an epoxy resin as a potting resin is injected into the resin filling portion 2 by a dispenser or the like.
At this time, when a convex lens is formed, as shown in FIG. 2, the epoxy resin 7 is injected from the end surface 3 of the case 1 so as to rise in a convex shape.

After that, when the epoxy resin 7 is heated and cured, the viscosity of the epoxy resin 7 is lowered and the case 1
However, since the end surface 3 is covered with the coating film 5, the epoxy resin 7 is repelled by the coating film 5 and maintains a convex shape. Then, the epoxy resin 7 is cured in a convex state, and a convex lens is formed in the resin filling portion 2.

Further, the coating film 5 on the end surface 3 of the case 1
Since the resin for potting is repelled by the resin, when potting with a dispenser or the like as shown in FIG. 3, the position of the needle 9 is slightly displaced from the resin-filled portion 2 of the case 1, and the resin 7 is removed from the end face 3 of the case 1. Even if is injected, the resin 7 flows into the resin filling portion 2 and a predetermined amount of resin 7
Can be reliably injected.

[0013]

As described above, in the method of forming a lens for a chip LED using the potting resin of the present invention, the end face of the case on the resin-filled portion side is coated with a substance having a small surface free energy, and then the resin-filled portion is coated. When pouring resin into the resin-filled part in a convex shape to pot the resin, even if the resin viscosity is lowered by heating and curing the resin after the pouring, the resin is still covered by the coating film on the end face of the case. It is repelled, holds the convex shape, and hardens in the convex state to easily form the convex lens of the chip LED.

As a result, the central luminous intensity of the LED product is improved due to the lens effect. Further, when potting with a dispenser or the like, even if the position of the needle is slightly shifted, the case end face repels the resin, so that a predetermined amount of resin can be surely injected into the resin filling portion of the case.

[Brief description of drawings]

FIG. 1 is an external perspective view of a case in a forming method of the present invention.

FIG. 2 is a cross-sectional view of essential parts showing a state after heating and curing a resin in the forming method of the present invention.

FIG. 3 is a cross-sectional view of essential parts showing a case where the injection position is displaced when the resin is injected into the resin-filled portion of the case.

FIG. 4 is a cross-sectional view of essential parts showing a state (a) in which a resin is injected into a resin-filled portion of a case and a state (b) after heating and curing in a forming method of a conventional example.

5A and 5B show a state in which a resin is injected into a resin-filled portion of a case, a state during heating and curing (b), and a state after heating and curing in another conventional forming method (FIG. c)
FIG.

[Explanation of symbols]

 1 Case 2 Resin Filling Part 3 End Face on Resin Filling Part 5 Coating Film 7 Resin

Claims (1)

[Claims] 1. A lens forming method for forming a lens of a chip LED by potting a resin on a resin-filled portion of a case provided with an LED light-emitting element, wherein a substance having a small surface free energy is formed on an end face of the case on the resin-filled portion side. A method for forming a lens of a chip LED using a potting resin, which comprises: coating a resin, then injecting a resin into a resin-filled portion of a case, and heating and curing the resin.